A marine vibrator has a hollow body formed of one shell or of two opposed shells defining an inner space therein with vibrator apparatus within the hollow body. At least one shell has a curved shape, and the shell can have a streamlined shape with relatively low hydrodynamic drag. Certain embodiments include one or more exterior control members to facilitate positioning of the vibrator in water. Other than their mating ends, when two shells are used the two shells may be different in shape and v...

A marine propeller includes a hub defining an axial direction of the propeller, a plurality of adjustable propeller blades disposed around the hub, and a blade setting adjusting arrangement. Each blade includes a blade-part and a root-part, the root-part being mounted in the hub and being turnable about an axis that defines an angle with the axial direction of the propeller.

A marine propeller using the circulation control principle of blowing tantially over a Coanda surface at the trailing edge of each blade to develop high blade lift (thrust). Each blade has internal chambers and two blowing slots so that blowing is controllable for forward and for reverse thrust without reversing rotational direction of the propeller. This propeller is capable of generating much greater thrust and ship speed at lower RPM and noise levels than conventional propellers.

A marine riser section which has an elongated light-weight composite shells is provided with a protective liner of elastomer, epoxy resin or metal. The choice of elastomers includes nitrile rubber, fluorinated rubber or chlorosulfonated polyethylene; the choice of resins includes an aromatic amine cured epoxy with an added styrene curing system; and the metals include steel or titanium alloys or electroless nickel coating.

A rubbery buckling-type marine fender such as cell-type hollow cylindrical marine fender, frustoconical-type hollow cylindrical marine fender, V-shaped marine fender or the like comprises a main rubber body portion, a securing flange portion, and a shock receiving portion, in which a rubber thickened region is formed in the inner peripheral surface of the main rubber body portion at a given position adjacent or close to a buckling point to prevent falling of reaction force during the buckling de...

A marine anchor has an anhedral fluke with a shank attached thereto including an anchor line attachment point. A rear plate assembly behind the fluke is inclined at an obtuse angle .alpha. to the fluke and serves to provide a turning moment about the attachment point countering turning moments produced by friction effect on the fluke and the shank and by edge resistance during anchor burial to give improved anchor holding power while soil escapes the passage between the rear assembly and the flu...

A marine drive for coupling a marine engine drive ring to a transmission drive shaft. A spider drive engages the drive ring and is provided with a plurality of rubber-cushioned trapezoidal lugs. The drive shaft is held in the spider drive by a central locking hub which is drawn tightly onto the drive shaft due to the tapered aperture in the spider drive. Wear-causing slippage of the drive shaft is thereby reduced.

A marine connector that facilitates docking of large floating objects during a sea state that produces significant relative motion between the two objects. A toggle nose is mounted on one floating object and a mating device, a toggle nose receiver, is mounted on the second floating object. The toggle nose contains a toggle mechanism that extends and retracts two opposed transverse pins having conical ends. The toggle nose receiver is provided with corresponding conical sockets to receive the end...

Method and apparatus for preventing the buckling of a pipeline (10) on either side of a localised zone of increased stiffness in the pipeline (such as a buckle arrester (12)) when the pipeline is bent around an arcuate path, in which packing elements (14) are located between the pipeline and a pipeline bearing surface (20) defining the arcuate pipeline path on either side of the zone of increased stiffness so as to vary the radius of curvature of the pipeline between a first, greatest value adja...

A top coat paint for ships' hulls comprising a. a film-forming copolymer containing from more than 50 up to 80 per cent by weight of units of at least one tri-organo tin salt of an olefinically unsaturated carboxylic acid, the balance of the copolymer being units of at least one olefinically unsaturated comonomer, B. a substantially water insoluble metalliferous pigment capable of reacting with sea-water to form a water-soluble metal compound, and C. a hydrophobic organic retarder for retarding ...